Electrical testing instrument having insulation piercing and wire gripping means



'sfpn 29, 1953 c. w. HUDLow 2,654,076 ELECTRICAL TING INSTRUMENT HAVING INSULATION PIER NG D WIRE GRI NG MEANS ed Feb. 9, l

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INVENTOR YA/R W. Afl/0l 0W,

ATTORNEY i Patented Sept. 29, 1953 GRIPPING MEAN S ELECTRICAL TESTDIG INSTRUMENT HAV- ING INSULATION PIERCING AND WIRE Clair W. Hudlow, Washington, D. C.; Matthew f' i J. OCallaghan, Jr., administrator of said Clair W. Hudlow, deceased, assigner of one-third to ,V Eleanor Dorr, Washington, D. C., one-third to l Ruth Wallace, Greenbelt, and one-third to Lucille Stumpf, Takoma Park, Md.

Application February 9, 1951, Serial No. 210,122

4 Claims. (Cl. 339-108) The present invention relates to an electrical testing instrument and it consists in the combinations, constructions and arrangements of parts herein described and claimed.

Generally there is provided an elongated cylindrical handle of dielectric material having a centrally and longitudinally disposed channel therein. In the outer end of the handle there is frictionally engaged the inner end of a hollow metallic cylinder whose outer portion is exteriorly threaded for engagement with an interiorlyV threaded extension member of dielectric material. The extension piece is inwardly tapered at its outer end and is provided with a centrally disposed passageway and a hollow interior. In the hollow interior of the extension piece there is provided a cylindrical abutment which has a flat inner surface which bears against the outer end of the metallic cylindrical member and which is provided with a frustro-conically shaped recess in its outer face. A substantially U-shaped testing member is provided with a pair of substantially parallel leg members which extend outwardly through the opening in extension device and with a rounded bight portion. A reinforcing member for the testing member encompasses a portion of each of the legs of the testing member and is also provided with a rounded bight portion which is closely aligned with the bight portion of the testing member and the bight portion of the reinforcing member is positioned within the frustro-conically shaped recess whereby outward pressure upon the abutment will cause the legs of the reinforcing member and consequently the legs of the testing member to be forced together. The legs of the testing member are each substantially semicircular in cross sectional area as are the legs of the encompassing reinforcing member and the outer portions of the legs of the testing member are each serrated. An aligning member is positioned between the inner faces of the inward portion of the legs of the testing member and is provided with an enlarged head which lies within the hollow portion of the extension piece to maintain the same against accidental loss. A lead wire extends through the handle, the metallic cylindrical member and the abutment and is soldered to the bight portion of the reinforcing member. The device is so constructed that it may be used in conventional manner or again either of the legs, which are pointed, of the testing member may be utilized to penetrate through ordinary insulation to make contact with the wire embedded thereinv and, finally, the legs may be forced over opposite sides of a wire whereupon the serrations will assist in maintaining the device in gripping contact with such wire without any extraneous manipulation of the device.

It is accordingly an object of the invention to provide a device of the character set forth which is simple in construction, inexpensive to manufacture and yet effective and efficient in use.

Another object of the invention is the provision of a novel and compact electrical testing implement.

A further object of the invention is the provision, in a device of the character set forth, of novel gripping legs forming a part of the invention.

A further object of the invention is the provision of novel means, in a device of the character set forth, for maintaining a pair of testing legs ln normally inwardly biased condition.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawing, in which:

Figure 1 isa vertical longitudinal sectional view of an embodiment of the invention,

Figure 2 is an elevational view of a reinforcing member forming a part of the invention,

Figure 3 is an elevational view of a testing member forming a part of the invention,

Figure 4 is a perspective view of an aligning member forming a part of the invention,

Figure 5 is an elevational view of a metallic cylindrical connecting member forming a part of the invention,

Figure 6 is an enlarged elevational View of an extension piece forming a part of the invention,

Figure 7 is an elevational view of an abutment or actuating collar forming a part of the invention,

Figure 8 is an enlarged fragmentary elevational view, partly in section, illustrating one manner of utilizing the invention, and

Figure 9 is an enlarged sectionalview taken along line 9-9 of Figure l.

Referring more particularly to the drawing, there is shown therein an'elongated cylindrical handle Iii of dielectric material having a centrally disposed channel Il therein. The outer end of the handle I0 is provided with a cylindrica1 recess I2 for the frictional reception therein of the inner portion I3 of a metallic cylindrical member generally indicated at I4, and whose outer portion is exteriorly threaded, as indicated at I5.

The member i4 is provided with a centrally disposed longitudinally extending channel I6 which is adapted to communicate with the channel II in the handle I0.

An extension piece Il of the same outer diameter as the handle Il) is interiorly threaded for the reception of the threads I on the connecting member I4. The member I1 is of die electric material and is preferably formed with an inwardly tapering outer end Il?. Y Y u ber I1 is provided with a hollow interior and with a centrally disposed opening in its forward end which communicates with the interior. K

A substantially U-shaped testing mel'rliaerV is generally indicated at I9 and fs provided with a pair of substantially paralliel legs IIT and' ai.v rounded bight portion 2|. Each of lege 2@ is substantially semi-circular in cross sectional area and arranged in such marmer that'the heli-e low faces of such legs are presented to eachother.

A reinforcing member is generally indicated at A22 and is likewise substantially U-shaped and provided with a pair' of: legs 22 which are substantially shorter' than the legs 20" and` likewise substantiallyv semielrcularin cross. sectional" area and arranged to encompass. the' rearward' portions of the legs 2li. The. member' 22* is likewise provided with a` rounded bight portion 2tl which encompassesv in' close alignment the bi'ght' p0rtion 2I' of: the member" le. A lead wire is centrally am'xe'dto the bightportion 2r, as indicated at 25 and extends inwardly through the channels` I6` and I`I".4 'Ihe abutting edges of' the' legs 2U are eacl'r provided' with scrrations. 26;

Within the interior of the exter'rsion'L piece' I1 and abutting the outer. end of the connecting member IH i`s a cylindrical' actuating.' member 21 having; a flattened rear face 28" ard' provided' with .a'frustro-conically shaped'recess 29 in its forward `face.

A cylindrical' aligning' member 30 lies between 'the inner portions of the legs 2U and has integrally formed' therewith an enlarged head' 31' which isadapted to remain in the interior otthe extension member I1" and within the bight portions 2I and.` of 'the members. I'9`andl22", respectively.

In operation, it' willbe apparent' that theentlre device may be manipulated as aunit by grasping the handle Ill in conventional' manner andV that the legs ZUmay be utilized' for'testi'ngpurposes inthe convention'almaxmer. by merely touching the. same to-wires and' the. like to. be tested'. It will also be seen that the bight portion 2T ot themember 22 will abut the sidesofthe recess 29` at its outer portions and-'thatwhentheemember Id'is screwed into'the extension piece IT'that it' wil1 abut against the flat face. 2U of the member 21'therebyforcingthe' legs 23`of the member 22 toward each other and thus, in turn, forcing thelegs 20`toward` cach' other; it willbe apparent thatA the legs' 2D? willi a't' ailA times be biased toward each'other'an'd' th'a'theiice when itk is desired to contactand. grip a; wire'- to be tested, it is only necessary tofor'ce thewir'e b`e`- tween-the pointed outer endsof 'thelegsiZIi "'whereupontheserrations' 26; will act in conjunction with the inward; pressure' appliedI to`V the. legs' 2U by the member Z'Ifto securely'grip'such wirean'd maintain the entiredevice' in sucl'r gripping contact without the' -need` for'any extraneous devices.'

Itf will alsoV beapparent th'at'in'orderf to' keep the-serrations 264 onthe `legs 2`li"'in'V proper coacting relationship,v the cylindrical member' 3Ifwill prevent the sides of the legs 20 from gettingout ofalignment'since theinnercon'cavel faces oi the lege- 201= will beL inf engagement'-h with' the The member 30. The enlarged head polion 3| acts to retain the member 30 at all times n its proper position at the4 limer portions of th legs 20 and further acts to prevent loss of the seme outwardly between the legs 20 which might otherwise occur if the head 3| were not rovided.

Another feature of the invention is the pointed outer endsof the legs 20 which alow the device to penetrate through, for example@ insulation 32 to contact a wire 33 embedded therein, as illustraten, for example, in Figure 8 of the rawing.

While'Y but one4 form of the invention as been Shown and described herein, it will be readily apparent to those skilled in the art that many minor modicati'ons may be made without de-T`\ parting from the spirit of the invention or the Scope oftll'eappeded claims.

What-is1 claimed is l'. A device of the character described comprising. an elongated cylindrical handle of dielectric material' having a centrally disposed; longitudinal channel' therethroughA and having a recess' in itsouter end, a hollow' cylindrical extension piece of dielectric materiali of'identicaljout'er diameter with said handle, a metallic hollow cylindrical connector threaded into said extension piece at the outer portion of. the connector and said connectar having itsv inner4 portion f rjictionaily receivable the recessi'n said handle, a' U'shap`ed testing' member having a' pair of substantially parallel legs extendingv outwardly of sai'd` exten'- S'br piece,A S'ad` l'e'gS" of lille testing member" Ch being semi-circular' in" cross' sectional area and having' their concave faces presented toward each other', a lead' wire extending through the chan-l nel in said handle and` through sai'd connector and having electrical' connection with' said' testi ing member, meansY for biasing' said l'eg's'of said testing" member toward' each other,I andl n'ie'arisl formaintaining' said legsv f said testing membei iii longitudinal' alignment, salicil laS't-entloned` means comprisingV a cylindrical tion'e'd between the inner portions" of saidY tkting-f member legs and' an enlarged' head' formed int'e'gially'with said body and positioned' within' the biglit portion of said testing. member.-

21 A-de`vice of the character described comprisi'rigfari' elongated cylindrical handle' of dielectric material having a centrally 'disposed' longitudinal channel therethroughand having a recess in it's outer end", a hollow cylindrical extension piece'oi dielectric material of identical' outer diameter with' said handle, a' IiietalllicV hollow` cylindrical Connector'- tlreadd'it said` extensin piede at the'outer' portion'of' the connector and'saidc'oxineet'dhliavng its' inner portieri( frietionally re'- ceivable'in the recessin'said handle, a U-shaped testing memberA having" a pairfofj substantially parallelA legs extending outwardly' ol." saidext'en'- siorr piece, said legs of the" testingn'i'emb'er each being semi-circular in cross' sectional area` and having theirc'oncave faces' presentedtowardeach other', a"leadwire extending through theicha'nnel in said' handle and through said connector and having electrical; connection with" said l testing member; means forbi'asing saidlegs ois'aicl'te'sting' member toward" each other; saidi me'ans'j including a4A reinforcing member' having a pair of legsllilewi'se semi-circular' in cross sectional area'. and sho'rterthan the 'legsof 'tlie'testingmemben anda bight portion 'of' similar shape to the bight port/ion of" thetesting member; said# reinforcing member" encompassing-'said testing member" iii close` relationship, and; a4 cylirll'lric'ra'l actuating member' having a fiat'in'ner face abuttingith'e outer endif the connector and having a frustro- @O nlcally saped recess in its outer face for recelvlng theein the bight portion of said reinforclng'membet. 3. A device of the character described compris- 111g an elorgated cylindrical handle of dielectric materialhafing a centrally disposed longitudinal Channel thecethrough and having a recess in its Outer end, a hollow cylindrical extension piece of dielectric material of identical outer diameter with said handle, a metallic hollow cylindrical connector threaded into said extension piece at theuter portion of the connector and said con- ,Qlitor having its inner portion frictionally receivable in the recess in said handle, a U-shaped testing member having a pair of substantially parallel legs extending outwardly of said extension piece, said legs of the testing member each being semi-circular in cross sectional area and having their concave faces presented toward each other, a lead wire extending through the channel in said handle and through said connector and having electrical connection with said testing member, means for biasing said legs of said testing member toward each other, said means including a reinforcing member having a pair of legs likewise semi-circular in cross sectional area and shorter than the legs of the testing member, and a bight portion of similar shape to the bight portion of the testing member, said reinforcing member encompassing said testing member in close relationship, a cylindrical actuating member having a flat inner face abutting the outer end of the connector and having a frustro-conically shaped recess in its outer face for receiving therein the bight portion of said reinforcing member, and means for maintaining said legs of said testing member in longitudinal alignment.

4. A device of the character described comprising an elongated cylindrical handle oi dielectric material having a centrally disposed longitudinal channel therethrough and having a recess in its outer end, a hollow cylindrical extension piece of dielectric material of identical outer diameter with said handle, a metallic hollow cylindrical connector threaded into said extension piece at 6 the outer portion of the connector and said connector having its inner portion frictionally receivable in the recess in said handle, a U-shaped testing member having a pair of substantially parallel legs extending outwardly of said extension piece, said legs of the testing member each being semi-circular in cross sectional area and having their concave faces presented toward each other, a lead wire extending through the channel in said handle and through said connector and having electrical connection with said testing member, means for biasing said legs of said testing member toward each other, said means including a reinforcing member having a pair of legs likewise semi-circular in cross sectional area and shorter than the legs of the testing member, and a bight portion of similar shape to the bight portion of the testing member, said reinforcing member encompassing said testing member in close relationship, a cylindrical actuating member having a iiat inner face abutting the outer end of the connector and having a frustro-conically shaped recess in its outer face for receiving therein the bight portion of said reinforcing member, and means for maintaining said legs of said testing member in longitudinal alignment, said last-mentioned means comprising a cylindrical body positioned between the inner portions of said testing member legs, and an enlarged head formed integrally with said body and positioned within the bight portion of said testing member.

CLAIR W. HU'DLOW.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,134,074 Chirelstein Oct. 25, 1938 2,518,489 Orlando Aug. 15, 1950 FOREIGN PATENTS Number Country Date 248,614 Switzerland Feb. 16, 1948 558,046 France May 16, 1923 646,578 France July 16, 1928 

